ATTENTIONAL EFFECTS OF SINGLE-DOSE TRIAZOLAM

1. While the effects of benzodiazepines on human memory have been exte nsively studied little is known about the effects of these agents on a ttentional processes. The authors studied the effects of a single dose of triazolam on selective visual-spatial attention using a double bli nd, placebo controlled design. 2. In each of 2 sessions 12 normal volu nteers ingested either 0.25 mg of triazolam or placebo. Attentional pe rformance was evaluated using two versions of the covert orienting par adigm which measured automatic (exogenous) and controlled (endogenous) aspects of attentional orienting, respectively. 3. Triazolam selectiv ely modified performance on automatic orienting to exogenous cues. Spe cifically, triazolam increased the facilitation of target detection se en at shorter (150 msec) SOA's. This may indicate an increase in facil itation and a reduction in inhibition or a slowing of the time course of the biphasic attentional effect normally resulting from exogenous c uing. 4. These results indicate the importance of using experimental p aradigms which effectively dissociate endogenous and exogenous mechani sms of spatial orienting in studies evaluating the effects of pharmaco logical agents on visual-spatial attention.